body{
    margin: 0;
    padding: 0;
    background-color: #f7f7f7;
}
.header_box{
    position: absolute;
    width: 100%;
    height: 120px;
    box-shadow: 0 1.5px 6px rgba(0, 0, 0, .3);
}
.logo_box{
    position: absolute;
    margin-top: 30px;
    margin-left: 25px;
}
.logo{
    display: block;
    width: 320px;
    font-size: 2em;
    color: white;
    text-decoration: none;
}
.login_box{
    float: right;
    margin-top: 30px;
    margin-right: 25px;
}
.login_box>.btn-secondary{
    background-color: rgba(0, 0, 0, .2);
    width: 90px;
    height: 40px;
}
.mask{
    position: fixed;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    background-color: rgba(0, 0, 0, 0.5);
}
.login_in{
    background-color: white;
    width: 450px;
    height: 350px;
    margin: 0 auto;
    margin-top: 15%;
}
.login_close{
    display: block;
    width: 20px;
    height: 20px;
    float: right;
    margin-right: 5px;
    background-image: url(../img/close.png);
    background-size: cover;
}
.login_in>img{
    width: 70px;
    float: left;
    margin-left: 30px;
    margin-top: 50px;
}
.login_form{
    width: 250px;
    margin-top: 30px;
    margin-left: 125px;
}
.login_form>input{
    margin-bottom: 2px;
}
.login_form>button{
    width: 250px;
    margin-top: 20px;
}

.tips_null{
    position: absolute;
    color: red;
    display: none;
    width: 150px;
    font-size: 0.8em;
    margin-top: -25px;
    margin-left: 10px;
}
.title_img{
    height: 150px;
    background-image: url(../img/title_img.jpg);
    background-size: cover;
}

.section_box{
    min-height: 1080px;
    /* background-image: url(../img/1F523135937-4.jpg); */
    /* background-image: linear-gradient(135deg, #667eea 0%, #764ba2 100%); */
    /* background-size: cover; */
    padding-top: 150px;

	width: 100%;
	height: 100vh;
	font-family: "Exo", sans-serif;
	color: #fff;
	background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
	background-size: 400% 400%;
	animation: gradientBG 15s ease infinite;
}


@keyframes gradientBG {
	0% {
		background-position: 0% 50%;
	}
	50% {
		background-position: 100% 50%;
	}
	100% {
		background-position: 0% 50%;
	}
}

.declaration_box{
    width: 740px;
    height: 300px;
    margin: 0 auto;
}
.declaration{
    padding-top: 100px;
}
.quick_into{
    width: 610px;
    margin: 0 auto;
}
.quick_into>.btn{
    width: 100px;
    height: 50px;
    margin-left: 100px;
    margin-right: 100px;
}

.footer_box{
    height: 200px;
}